Metal bonded product and method for producing metal bonded product

Abstract

To provide a metal bonded product wherein a large bonding area can be provided to achieve high bonding strength and coaxial accuracy can be easily achieved needing no positioning jig. A first taper portion 16 is formed on a side wall surface of the opening 13 of the ring-shaped metal member 12 , and multiple step-shaped bonding surfaces are formed thereon. An end of the cylindrical portion 11 has a second taper portion 17 with the same chamfer angle as that of the first taper portion 16 of the ring-shaped metal member 12 . The ring-shaped metal member 12 and the cylindrical metal member 11 are bonded to each other by press-fitting the cylindrical portion of the cylindrical metal member 11 in the opening 13 of the ring-shaped metal member 12 while applying a current to cause the side wall portion of the cylindrical portion of the cylindrical metal member 11 and the multiple step-shaped bonding surfaces of the first taper portion 16 to undergo plastic flow.

The invention claimed is: 
     
       1. A method for producing a metal bonded product, comprising the steps of:
 providing a first metal member having a circular opening and having a first taper portion on a side wall surface of the opening; 
 providing a second metal member having a cylindrical portion to be press-fitted in the opening, the second metal member having a second taper portion formed at an end of the cylindrical portion with a same chamfer angle as a chamfer angle of the first taper portion; 
 press-fitting the cylindrical portion in the opening; 
 bonding the first and second metal members to each other by applying a current between the first and second metal members; 
 wherein the first taper portion or the second taper portion has multiple step-shaped bonding surfaces and the bonding step includes the step of causing multiple step-shaped bonding surfaces, an edge of each step of the multiple step-shaped bonding surfaces is chamfered, to undergo plastic flow. 
 
     
     
       2. The method for producing a metal bonded product according to  claim 1 , wherein the first metal member is a ring-shaped metal member having the circular opening through its center. 
     
     
       3. The method for producing a metal bonded product according to  claim 1 , wherein the chamfer angle of the first taper portion, the chamfer angle of the second taper portion and a chamfer angle of the edge are approximately 15° to 60°. 
     
     
       4. The method for producing a metal bonded product according to  claim 3 , wherein the first metal member is a ring-shaped metal member having the circular opening through its center.